Re: Functional Origins of Aikido/Daito-Ryu Techniques
I might approach your question with a pragmatic answer. Just like the old sage when introduced to an herb he did not recognize, he simply asks , what is it good for".
I have found and continue to learn that virtually every principle in Yanagi as a Koryu art can be discovered in the first technique: Ikkyo. The first layer of learning is the kata. Not always the best application against a trained grappler. But the many variations of how to control an outstretched arm is a larger study. You can begin with jujitsu application, move to aikijutsu and ultimately Aiki no jutsu.
But neither can you make the one technique a stand-alone project or combat strategy. If uke's arm bends in a judo form of "pong energy" (often seen in rondori as elbows slightly raised) the ikkyo principle of "anvilling" may suffice but then again, other techniques in your quiver may be calling out to you.